I'm trying to set up a pane of glass for an airplane cockpit. It should be mostly transparent, with a bright specular reflection. I had something decent working, but it was using a glutSolidCube() for the pane of glass. I changed it to use GL_QUADS instead (since ultimately, I want to use GL_POLYGON and I thought I'd change as little as possible at first), and the specular reflection disappeared. Anyone know why?